Partner OCD in particular with dog hair such - struggling to support her and our 8 month baby

My partner has contamination OCD centered on dog hair, and it's gotten harder since our son was born 8 months ago:

• If I've been in a house with a dog, I am told to strip at the door and shower before touching anything.
• If someone else has been in my car, she checks and wipes the seats — any dog hair found and the whole car is seen as contaminated.
• Anything my parents bring for the baby as they have a dog treated as dirty even if straight from the shop, sits in a bag until wiped down with washing-up liquid.
• During bath time or nappy changes, if our son touches himself (completely normal at his age), she feels his hands need washing right after, like something dirty happened.

I get these are compulsions, not logic, and I want to support her without reinforcing the cycle by just doing what's "required" to avoid conflict. Has anyone navigated this, as the person with OCD or as their partner? What actually helped?